Living things [ edit ] A live frog levitates inside a 32 mm diameter vertical bore of a Bitter solenoid in a very strong magnetic field—about 16 teslas

The vast majority of metals are considered “not magnetic.” More accurately, most of these metals are paramagnetic.:

How do magnets work?

The earliest mention of the attraction of a needle is in a 1st-century work Lunheng ( Balanced Inquiries): "A lodestone attracts a needle." [10] Furlani, Edward P. (2001). Permanent Magnet and Electromechanical Devices: Materials, Analysis and Applications. London: Academic Press. ISBN 978-0-12-269951-1. Manufacturing Process of Sintered Neodymium Magnets". American Applied Materials Corporation. Archived from the original on 2015-05-26. Diamagnetism appears in all materials and is the tendency of a material to oppose an applied magnetic field, and therefore, to be repelled by a magnetic field. However, in a material with paramagnetic properties (that is, with a tendency to enhance an external magnetic field), the paramagnetic behavior dominates. [14] Thus, despite its universal occurrence, diamagnetic behavior is observed only in a purely diamagnetic material. In a diamagnetic material, there are no unpaired electrons, so the intrinsic electron magnetic moments cannot produce any bulk effect. In these cases, the magnetization arises from the electrons' orbital motions, which can be understood classically as follows: Research Funding for Rare Earth Free Permanent Magnets". ARPA-E. Archived from the original on 10 October 2013 . Retrieved 23 April 2013.

I.e., not only u A {\displaystyle u_{A}} and u B {\displaystyle u_{B}} must be substituted by α and β, respectively (the first entity means "spin up", the second one "spin down"), but also the sign + by the − sign, and finally r i by the discrete values s i (=± 1⁄ 2); thereby we have α ( + 1 / 2 ) = β ( − 1 / 2 ) = 1 {\displaystyle \alpha (+1/2)=\beta (-1/2)=1} and α ( − 1 / 2 ) = β ( + 1 / 2 ) = 0 {\displaystyle \alpha (-1/2)=\beta (+1/2)=0} . The " singlet state", i.e. the − sign, means: the spins are antiparallel, i.e. for the solid we have antiferromagnetism, and for two-atomic molecules one has diamagnetism. The tendency to form a (homoeopolar) chemical bond (this means: the formation of a symmetric molecular orbital, i.e. with the + sign) results through the Pauli principle automatically in an antisymmetric spin state (i.e. with the − sign). In contrast, the Coulomb repulsion of the electrons, i.e. the tendency that they try to avoid each other by this repulsion, would lead to an antisymmetric orbital function (i.e. with the − sign) of these two particles, and complementary to a symmetric spin function (i.e. with the + sign, one of the so-called " triplet functions"). Thus, now the spins would be parallel ( ferromagnetism in a solid, paramagnetism in two-atomic gases). Optically induced magnetism works when an electric current passes through a magnetic layer and the electric current becomes spin-polarized. The spin-polarized current will exert a spin-transfer torque (STT) on the magnetization. This phenomenon can also be generated inside a non-magnetic metal due to the spin–orbit coupling (SOC) Spin–orbit interaction, and the corresponding torque (spin–orbit torque (SOT)). Merzouki, Rochdi; Samantaray, Arun Kumar; Pathak, Pushparaj Mani (2012). Intelligent Mechatronic Systems: Modeling, Control and Diagnosis. Springer Science & Business Media. pp.403–405. ISBN 978-1447146285. In this approach, the divergence of the magnetization ∇· M inside a magnet is treated as a distribution of magnetic monopoles. This is a mathematical convenience and does not imply that there are actually monopoles in the magnet. If the magnetic-pole distribution is known, then the pole model gives the magnetic field H. Outside the magnet, the field B is proportional to H, while inside the magnetization must be added to H. An extension of this method that allows for internal magnetic charges is used in theories of ferromagnetism.

Magnetic metals

Warning issued around the ingestion of 'super strong' neodymium magnets often found in toys". NursingNotes. 2021-05-21 . Retrieved 2021-05-27.

a b c Chu, Steven. Critical Materials Strategy United States Department of Energy, December 2011. Accessed: 23 December 2011.Typical Physical and Chemical Properties of Some Magnetic Materials, Permanent Magnets Comparison and Selection. Neodymium magnets have higher remanence, much higher coercivity and energy product, but often lower Curie temperature than other types of magnets. Special neodymium magnet alloys that include terbium and dysprosium have been developed that have higher Curie temperature, allowing them to tolerate higher temperatures. [15] The table below compares the magnetic performance of neodymium magnets with other types of permanent magnets. r 1 , r 2 ) = 1 2 ( u A ( r 1 ) u B ( r 2 ) + u B ( r 1 ) u A ( r 2 ) ) {\displaystyle \psi (\mathbf {r} _{1},\,\,\mathbf {r} _{2})={\frac {1}{\sqrt {2}}}\,\,\left(u_{A}(\mathbf {r} _{1})u_{B}(\mathbf {r} _{2})+u_{B}(\mathbf {r} _{1})u_{A}(\mathbf {r} _{2})\right)} According to the Heitler–London theory, so-called two-body molecular σ {\displaystyle \sigma } -orbitals are formed, namely the resulting orbital is: Hewitt, Paul G. "Conceptual Physics." Addison-Wesley Publishing Company, Inc. 1998. https://worldcat.org/title/35808384